The performance of various aeration systems for treatment of two different industrial liquid effluents was performed and discussed in this work. Fixed, combined and diffused systems were chosen. The samples for different detention time were tested for BOD and COD, before and after aeration for these three systems. In diffused aeration system the inlet COD value is high and it has been reduced to low. The reduction of BOD in the diffused aeration system is high when compare to other traditional systems. The factor of safety for diffused aeration system handling high organic load has a factor of safety approximately equal to the other two systems. The test and power calcuation revealed that the diffused aeration system is more effective and economic among the aeration systems studied for an effluent of high organic load.